Well, the experiment turned out great. The cook was for a party yesterday hence the delay with getting back to posting. A good time was had by all. Now, down to business.
First let us talk about temperatures.
My MEATER kept dropping off so I don't have a temperature trace to share with you but I took these three photos within a minute of each other. The two thermometers on the side of the joint in the KK were measuring 73C while the one in the top was measuring 81C. The KK dome thermometer was measuring about 73C too while the grill grate thermometer was showing close to 100C. In some ways, the actual temp of the KK was not critical, what was more critical was getting the meat out when it was close to hitting the 55C target internal temperature. The KK was great, keeping a steady temp for the whole of the approx 3 hour cook.
I found this really thin needle temperature probe that my Husband bought years ago for poking into sousvide bags to check the temp of the contents. Here is the reading on the sous vide joint after about 5 hours in the water bath. A check on the KK joint showed a range of temps from 57C at the thinnest end to 52C in the centre. The good news is that the internal temp was consistent across the joint, staying the same as I pulled the needle from the centre to the edge.
I rested the joints over night in the fridge and only cut them just before we had to serve them to the guests. Nail biting!
Here are the two joints. The right hand one was cooked in the KK. It did have a faint smell of smoke so we did get some smoke into it from the smoke pot, even at that low temperature.
And here are the results. KK joint on the right.
Sliced up the sous vide joint was consistently pinker (lower pile in the pic below) but I suspect I could have got closer to that result in the KK by going for a slightly lower target temp.
Learning? Sous vide is easier. Set and forget the water bath temp and get your meat out when you are ready. KK is more fun and does almost as good a job without having to buy extra equipment. Also have opportunity to introduce smoke when using the KK and I could have used the cold smoke generator to get a more pronounced smoke flavour. All in all I was very happy with the results from both methods and our guests loved this, new to us Brits, Italian method of cutting roast beef.